U.S. patent number 4,119,276 [Application Number 05/819,661] was granted by the patent office on 1978-10-10 for laminar stream spout attachment.
Invention is credited to Walter R. Nelson.
United States Patent |
4,119,276 |
Nelson |
October 10, 1978 |
Laminar stream spout attachment
Abstract
A laminar stream spout attachment which may be threadedly
secured to a faucet spout includes a pair of parallel, spaced-apart
perforated plates and a pair of screens positioned downstream from
the plates. The perforated plates distribute the flow velocity
profile more uniformly across the stream diameter and the screens
operate to further trim the stream to provide a high quality stream
which is clear, straight, free of mist and spray, soft and
essentially splash free.
Inventors: |
Nelson; Walter R. (Gardena,
CA) |
Family
ID: |
24660263 |
Appl.
No.: |
05/819,661 |
Filed: |
July 27, 1977 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
Issue Date |
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663041 |
Mar 2, 1976 |
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Current U.S.
Class: |
239/590.3;
239/590.5 |
Current CPC
Class: |
E03C
1/086 (20130101) |
Current International
Class: |
E03C
1/086 (20060101); E03C 1/02 (20060101); B05B
001/34 () |
Field of
Search: |
;239/428.5,553.3,590.3,590.5 |
References Cited
[Referenced By]
U.S. Patent Documents
Primary Examiner: Love; John J.
Attorney, Agent or Firm: Fraser and Bogucki
Parent Case Text
RELATED APPLICATION
This is a continuation application of Ser. No. 663,041 filed Mar.
2, 1976.
Claims
What is claimed is:
1. A laminar stream spout attachment comprising:
a housing defining a closed, nonapertured sidewall about a
cylindrical, smooth central passage having an inlet and an outlet
longitudinally spaced downstream from the inlet;
at least two longitudinally spaced-apart, parallel plates
positioned within and extending across the central passage, each of
the plates having small apertures therethrough distributed
substantially uniformly throughout the plates, the area of the
apertures in each plate being between about 30% and about 35% of
the total plate area thereby reshaping the flow velocity profile of
the stream in the central passage to have greater uniformity across
the central passage, the longitudinal spacing between the plates
being between about one aperture diameter and about three aperture
diameters; and
at least two longitudinally spaced, parallel screens positioned
within and extending across the central passage the screens being
longitudinally spaced downstream from the plates.
2. The laminar stream spout attachment according to claim 1 above,
wherein the plates are substantially flat and of uniform thickness
throughout and wherein the density of apertures in the plates is at
least 500 apertures per square inch (77.5 apertures per square
cm).
3. A laminar stream spout attachment comprising:
a housing defining a closed, nonapertured sidewall about a
cylindrical, smooth-walled central passage having an inlet and an
outlet longitudinally spaced downstream from the inlet;
at least three longitudinally spaced-apart parallel plates
positioned within and extending across the central passage, each of
the plates having small apertures therethrough distributed
substantially uniformly throughout the plates, the area of the
apertures in each plate being between about 30% and about 35 % of
the total area of the plate, the plates being separated a distance
between about one aperture diameter and about three aperture
diameter; and
at least one screen positioned within and extending across the
central passage, the at least one screen being longitudinally
spaced downstream from the plates and parallel thereto.
4. The laminar stream spout attachment according to claim 3 above,
wherein the plates are substantially flat and of uniform thickness
throughout and wherein the density of apertures in the plates is at
least 500 apertures per square inch (77.5 apertures per square
cm).
5. A laminar stream spout attachment comprising:
a generally cylindrical nonapertured housing shell having an open
inlet end adapted for coupling to a spout and an open outlet end
longitudinally spaced downstream from the inlet end, the shell
terminating at the outlet end in a flange extending inward a short
distance toward a central passage through the shell;
a notched, annular cartridge disposed in mating relationship with
the interior of the shell and in abutment with the flange, the
notched cartridge having an annular notch in an interior surface
thereof beginning at a position longitudinally spaced upstream from
the flange and extending toward the inlet end, the notched
cartridge having interior sidewalls defining a lower portion of a
central passage between the notch and the flange;
a plurality of flat plates positioned to intercept the central
passage in the vicinity of the annular notch, each of the plates
having a plurality of small apertures distributed substantially
uniformly therethrough with a total aperture area between 30% and
35% of the area of a plate;
at least one screen positioned longitudinally downstream of the
plates to intercept the central passage in the vicinity of the
annular notch; and
a plurality of annular spacer washers disposed within the notch
between each adjacent plate and screen, the spacer washers having a
thickness between about one aperture diameter and about three
aperture diameters in the longitudinal direction and an interior
circumference in substantial conformity and alignment with the
lower portion of the central passage to complete the definition of
a central passage through the housing shell past the plates and at
least one screen, the central passage having a straight, smooth
boundary in the longitudinal direction and a substantially uniform
cross-sectional area, the spout attachment providing fluid jet from
the outlet end with a high quality laminar flow having a
substantially uniform flow velocity throughout a cross-sectional
area coterminous with the central passage.
Description
BACKGROUND OF THE INVENTION
1. Field of the invention
This invention relates to attachments to faucet spouts to modify
the stream of a fluid flowing therethrough and more particularly to
a non-aerating spout attachment having a plurality of parallel,
spaced-apart, apertured, flat plates and at least one screen spaced
downstream from the plates.
2. Description of the Prior Art
Present day faucet spouts typically have a threaded coupling on the
end thereof to receive a mating threaded end of a spout attachment
device. Known spout attachments operate to modify the nature or
quality of the stream emanating from a spout by aerating the
stream, reducing the turbulence of the stream, or otherwise
changing the characteristics thereof as it flows through the
attachment. However, no known spout attachment provides a high
quality non-aerated stream which is clear, free of mist, spray or
other turbulence, and so soft that it is essentially splash free
with the economy and efficiency of the attachment taught and
claimed herein.
SUMMARY OF THE INVENTION
A spout attachment in accordance with the invention provides a
laminar stream which is free of turbulence and so soft that it is
essentially splash free without aeration. The attachment includes a
housing defining a closed, nonapertured sidewall about a central
passage having an inlet end and an outlet end longitudinally spaced
downstream from the inlet and, at least two longitudinally
spaced-apart, parallel flat plates positioned within and extending
across the central passage, each of the plates having small
apertures therethrough distributed substantially uniformly
throughout the plates, and at least one longitudinally spaced
screen positioned within and extending across the central aperture,
the screen or screens being longitudinally spaced downstream from
the plates and parallel therewith. The central passage has
substantially straight and smooth sidewalls in the longitudinal
direction and a substantially constant crosssectional area
throughout its length. A large number of apertures are uniformly
distributed throughout each plate to provide a substantially
uniform flow velocity profile across the entire central passage and
have a total aperture area between 30% and 35% of the total area of
each plate. To obtain the desired flow velocity profile, the
apertured plates are preferably separated by a distance of at least
approximately one aperture diameter, but no more than about 21/2 to
3 aperture diameters.
BRIEF DESCRIPTION OF THE DRAWINGS
A better understanding of the invention may be had from a
consideration of the following detailed description taken in
conjunction with the accompanying drawings in which:
FIG. 1 is a side view, partially broken away, of a laminar stream
spout attachment in accordance with the invention;
FIG. 2 is a plan view of an apertured plate for the spout
attachment shown in FIG. 1
FIG. 3 is a plan view of a screen for the spout attachment shown in
FIG. 1 and
FIG. 4 is a diagram illustrating the improved flow characteristics
provided by the spout attachment shown in FIG. 1.
DETAILED DESCRIPTION
As shown in FIG. 1, a laminar stream spout attachment 10 in
accordance with the invention includes a housing 12 having a
housing shell 14, an upper cartridge 16, and a lower cartridge 18,
a flow control assembly 20 and a laminar stream assembly 22. The
flow control assembly 20 is not an essential feature of the present
invention and may be of the type described in copending application
Ser. No. 558,071 filed Mar. 13, 1975 for FLOW CONTROL DEVICE.
The housing shell 14 extends with a generally cylindrical shape
from an inlet end 30 to an outlet end 32 longitudinally spaced
downstream of the inlet end 30. External threads 34 are provided on
the shell 14 near the inlet end 30 for coupling to a faucet spout
indicated at 36. It will be appreciated that internal threads might
alternatively be located adjacent the inlet end 30. At the outlet
end 32, the shell 14 terminates in a flange 38 which extends
radially inward toward a central passage 40. The lower cartridge 18
is a resilient, generally annular member having an internal
circumference 50 and an annular notch 52 in the internal
circumference 50. The lower cartridge 18 is disposed in abutment
with an inside surface of flange 38 and also in abutment with the
inside cylindrical sidewall of housing shell 14. The notch 52
extends longitudinally from a position spaced a short distance from
flange 38 to the end of cartridge 18 adjacent the inlet end 30. The
upper cartridge 16 is a resilient generally annular member having a
notch 52 mating with lower cartridge 18 in a lap joint and extends
in mating relationship with the interior sidewall of shell 14
longitudinally upstream from the notch 52 to an end 54 adjacent the
inlet end 30 of spout attachment 10. A washer 56 is disposed
adjacent the end 54 to make a sealing compression coupling between
the end 54 and a spout 36 to maintain the cartridges 16 and 18 in
contact with each other as well as flange 38. Two diametrically
opposed mating and notch pairs (not shown) may be positioned along
a mating surface 58 between the upper and lower cartridges 16, 18
to couple the two cartridges together and prevent relative rotation
therebetween. An interior surface 60 of upper cartridge 16 is
substantially coterminous with the interior surface 50 of lower
cartridge 18 to provide the central passage 40 with nearly equal
cross-sectional areas on opposite upstream and downstream sides of
the laminar stream assembly 22.
The laminar stream assembly 22 extends from a downstream end 62 of
upper cartridge 16 longitudinally downstream toward a downstream
termination of notch 52 at a surface 64. The laminar stream
assembly 22 includes two flat, parallel, spaced-apart apertured
plates 70, two flat, parallel, spacedapart screens 72 and annular
spacer rings 74 positioned between each adjacent pair of plates 70
and screens 72. While two plates 70 and two screens 72 are
illustrated by way of example, it should be appreciated that the
number of each may be increased without detracting from the
performance of the invention. In fact, it has been found that only
one screen 72 is required if at least three perforated plates 70
are employed in the laminar stream assembly 22.
It is important that the spacer washers 74 have an internal
circumference which is co-extensive with internal surfaces 50 and
60 to provide the central passage 40 with straight smooth walls in
the longitudinal direction and a uniform cross-sectional area
throughout the region of the laminar stream assembly 22.
Referring more particularly to FIG. 2, in a preferred example, the
flat, circular plates 70 are made from brass sheet or strip with a
thickness of about 0.016 inch (0.041 cm). The apertures 78 through
plates 70 are arranged in a matrix of rows and columns with a
uniform center-to-center spacing of about 0.044 inch (0.112 cm)
along both the rows and columns to provide a density of 500
apertures per square inch (77.5 apertures per square cm). With an
aperture diameter of 0.028 inch (0.071 cm) the total area of the
apertures 78 is approximately 31% of the total area of each plate
70. It has been found that in order to obtain the high quality,
non-turbulent laminar flow of which this invention is capable, the
total area of the apertures of each plate should be between 30% and
35% of the total area of each plate. It is also important that
there be a large number of small holes uniformly distributed across
the entire portion of a plate 70 which intercepts the central
passage 40, although the exact pattern in which the apertures 78
are arranged is not critical.
It is furthermore necessary that the distance between plates 70
relative to the diameter of the apertures 78 be such as to enable
the stream to adjust and redistribute after it passes through the
first or upstream plate to provide the desired uniform velocity
profile. It has been determined that the plate separation distance
should fall between about one aperture diameter and about 21/2 or 3
aperture diameters. Thus, in the embodiment under discussion, the
distance between plates may range from about 0.028 inch (0.071 cm)
to about 0.084 inch (0.213cm). In accordance with one practical
example of the invention, a distance of about 0.050 inch (0.127 cm)
is employed. The same distance separates the lower plate 70 from
the upper screen 72 and applies as well to the distance between the
two screens 72. Thus, all of the spacers 74 have about the same
height of 0.050 inch (0.127 cm).
Referring now to FIG. 3, in the preferred example, each screen 72
has a 40-square mesh and is made from monel or stainless steel wire
having a diameter of 0.010 inch (0.025 cm). In this example, each
of the screens 72 is in the shape of a flat circle. It has been
found that only one screen 72 is sufficient if at least three
plates 70 are employed in the attachment 10.
The substantial improvement in stream quality which is obtained
with the spout attachment 10 in accordance with the invention may
be further understood with reference to the diagram shown in FIG.
4. The horizontally extending dimension represents distance along a
diameter of the central passage 40 adjacent the outlet end 32 with
one extremity of the diameter indicated by 0, the other extremity
of the diameter indicated by D, and the circular center indicated
at C. The vertical axis indicates a flow velocity profile
increasing vertically upward from 0 at the horizontal axis. As
indicated by curve 90, a fluid stream with laminar flow typically
has a parabolically shaped flow pattern with substantially zero
flow adjacent the sidewall and a maximum flow velocity near the
center of the flow passage. However, the parallel spaced-apart
plates 70 and screens 72 of the present invention modify the flow
velocity pattern and redistribute the stream kinetic energy to
provide a much more uniform and constant flow velocity across the
entire cross-sectional area of the central passage 40. As a result,
the flow velocity profile indicated by curve 92 is attained with a
much broader, flatter and lower magnitude peak. Because the
velocity is more uniformly distributed over the entire
crosssectional area of the stream, the maximum velocity is reduced
to provide a softer, essentially splash free stream and turbulence
resulting from flow velocity changes across a diametric plane of
the stream is substantially eliminated.
Although a laminar stream spout attachment in accordance with the
invention has been described and illustrated for the purpose of
enabling a person of ordinary skill in the art to make and use the
invention, it will be appreciated that the invention is not limited
thereto. Accordingly, any modifications, variations or equivalent
arrangements within the scope of the attached claims should be
considered to be within the scope of the invention.
* * * * *